• Benjamin D. Herson, Jeff Deck

In 2008 Jeff Deck, at the time a Boston-area editor sensitive to misspellings, noticed a sign. “Private Property: No Tresspassing” it read. In his words, “the extra s seemed to mock me.”

The mockery led to a mission: Deck formed the Typo Eradication Advancement League. He recruited longtime friend Benjamin Herson to be a Sancho Panza-ish sidekick in his quixotic quest to cross the country to find (and to fix, if possible) public typos.

The journey led to a blog. The blog led to a book.

Deck and Herson will be in town on Monday, August 30, at Borders in Lincoln Park to promote The Great Typo Hunt: Two Friends Changing the World, One Correction at a Time (Crown Publishers).

(Only one Chicago typo made the book: “Milwuakee Furniture.” Must’ve been a short stay here.)

The book itself is admirably typo free. However, there is this . . .